This invention is related to laboratory bench assemblies, and more specifically, to a dental laboratory bench having novel exhaust hoods for use with various grinding stations.
In the finishing and polishing of dentures and the like it has been found desirable to collect as much of the precious metal dust which the lathes would grind away during the polishing and finishing process for later salvage of the precious metal as well as retaining a clean environment in the laboratory. In the past, this dust has been collected through dust hoods which were simply conduits connected to a source of negative air pressure. The dust-laden air would flow through a filter and out an exhaust to the open air. The hoods and lathes were permanent and fixed and took up considerable bench space. The dust was collected in a filter which was normally a conventional cloth bag or simply a rectangular disposable filter. By either method, the precious metal dust collected from various stations was combined into a single air flow which made a pass through a single series of filters trapping the precious metal and other dust particles in the filter, the air flow being exhausted. Thus, the air intake of a plurality of stations was combined into one air stream to go through the filter. Of course, with such arrangement the filter of the prior art dust became frequently clogged and in need of replacement, as it constituted a single pathway for the whole of the dust thus collected. Mechanical shakers were employed to dislodge some of the dust to extend the life of the filters somewhat. This practice proved to be rather inefficient, dislodging only the large dust particles, leaving the smaller particles still blocking the air flow.